Differential unmanned vehicle pose estimation method, system and device based on slip ratio correction

Abstract

The present application relates to the technical field of unmanned vehicle pose estimation, and provides a differential unmanned vehicle pose estimation method, system and device based on slip ratio correction. The method comprises the following steps: simplifying the kinematic model of the differential unmanned vehicle according to the vehicle motion principle; obtaining the left and right wheel accelerations and speeds; calculating the tire slip ratio according to the left and right wheel accelerations and speeds and the kinematic model of the differential unmanned vehicle; obtaining the vehicle pose angle using a gyroscope; determining whether the difference between the left and right wheel accelerations is greater than a threshold value, and if the difference is greater than the threshold value, updating according to the turning working condition formula based on slip ratio correction; otherwise, updating according to the straight-line driving working condition formula based on slip ratio correction; updating the value according to the odometer to obtain the current pose estimation of the unmanned vehicle. The present application fuses the information transmitted back by the accelerometer, wheel speed sensor and gyroscope on the vehicle in real time through an algorithm, realizes the correction of the wheel speed information, and can effectively improve the accuracy of vehicle pose estimation in the case of satellite denial.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unmanned vehicle pose estimation, and provides a differential unmanned vehicle pose estimation method, system and device based on slip rate correction. BACKGROUND

[0002] The pose information of an unmanned vehicle mainly includes vehicle speed, position of the vehicle body from the starting point, and vehicle body attitude, etc. During the driving of the unmanned vehicle, real-time acquisition of accurate and reliable vehicle body pose information can greatly improve the control accuracy of unmanned driving. At present, the combined navigation combining a global satellite navigation system (GNSS) and an inertial navigation system (INS) is widely applied to unmanned vehicles due to its high accuracy and low cost. However, in satellite-denied environments such as mines and tunnels, the use of satellite navigation systems is limited, and the accuracy of GNSS / INS combined navigation cannot be guaranteed. Therefore, other sensors need to be added to the unmanned vehicle to compensate for the decrease in the accuracy of combined navigation in the satellite-denied situation.

[0003] Currently, in most inertial navigation systems (INS) on the market, the influence of the slip rate is ignored when calculating the driving mileage of the vehicle, resulting in a large error in the estimation of the vehicle body pose, which seriously affects the autonomous driving accuracy of the unmanned vehicle. Accelerometers, wheel speed sensors and gyroscopes are widely used in the field of unmanned vehicles due to their low price, strong anti-interference and high product maturity. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the related art. To this end, the present application provides a differential unmanned vehicle pose estimation method and system based on slip rate correction, which realizes the correction of wheel speed information and can effectively improve the accuracy of vehicle pose estimation in the satellite-denied situation.

[0005] The present application provides a differential unmanned vehicle pose estimation method based on slip rate correction, comprising:

[0006] S1: simplifying the kinematic model of the differential unmanned vehicle according to the principle of vehicle motion;

[0007] S2: installing an acceleration sensor on the unmanned vehicle to obtain the left wheel acceleration and the right wheel acceleration;

[0008] S3: installing a speed sensor on the unmanned vehicle to obtain the left wheel speed and the right wheel speed;

[0009] S4: calculating the tire slip rate according to the left wheel acceleration, the right wheel acceleration, the left wheel speed, the right wheel speed and the kinematic model of the differential unmanned vehicle;

[0010] S5: installing a gyroscope in the middle of the unmanned vehicle to obtain the pose angle of the vehicle using the gyroscope;

[0011] S6: judging whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold value, if the difference is greater than the threshold value, updating the odometer according to the turning working condition formula based on the slip rate correction; otherwise, updating the odometer according to the straight line driving working condition formula based on the slip rate correction, to obtain an updated value;

[0012] S7: obtaining the current pose estimation of the unmanned vehicle according to the odometer updated value.

[0013] According to the slip rate correction based differential unmanned vehicle pose estimation method provided by the application, all the wheels on the left side are replaced by one wheel, all the wheels on the right side are replaced by one wheel, and the vehicle body is replaced by a rigid body.

[0014] According to the slip rate correction based differential unmanned vehicle pose estimation method provided by the application, step S2 comprises:

[0015] An acceleration sensor is installed on the vehicle body beside the left wheel to obtain the left wheel acceleration, and an acceleration sensor is installed on the vehicle body beside the right wheel to obtain the right wheel acceleration.

[0016] Step S3 comprises:

[0017] A speed sensor is installed on the left wheel to obtain the left wheel speed, and a speed sensor is installed on the right wheel to obtain the right wheel speed.

[0018] According to the slip rate correction based differential unmanned vehicle pose estimation method provided by the application, step S4 comprises: when the unmanned vehicle is in a driving state, the slip rate calculation formula of the left wheel is:

[0019]

[0020] wherein, is the slip rate of the left wheel at the time t when driving; is the slip rate of the left wheel at the time t when driving; is the wheel speed of the left wheel at the time t when driving, is the wheel speed of the left wheel at the time t when driving, is the acceleration of the left wheel at the time t when driving, is the acceleration of the left wheel at the time t when driving, is the wheel speed of the left wheel at the time t when driving, is the wheel speed of the left wheel at the time t when driving, is the acceleration of the left wheel at the time t when driving, is the acceleration of the left wheel at the time t when driving, is the time interval, is the time;

[0021] The slip rate calculation formula of the right wheel is:

[0022]

[0023] wherein, is the slip rate of the right wheel at the time t when driving, Slip rate at the moment; When driving, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

[0024] According to a method for estimating the position of a differential unmanned vehicle based on slip rate correction provided by the present invention, step S6 includes: threshold Determined according to the maximum driving speed of the unmanned vehicle chassis, the formula is:

[0025]

[0026] in, is the maximum speed of the unmanned vehicle chassis;

[0027] When the difference between the left wheel acceleration and the right wheel acceleration is greater than the threshold, the slip-rate-corrected turning odometer update formula is as follows:

[0028]

[0029] in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For the The position angle of the autonomous vehicle at the moment; is the wheelbase, For The corrected displacement of the left wheel during the time period, For The corrected displacement of the right wheel during the time period; the unmanned vehicle's forward direction is direction positive direction, The positive direction is the right turn direction of the unmanned vehicle. Direction and The directions are perpendicular to each other, For time;

[0030] When the difference between the left wheel acceleration and the right wheel acceleration is not greater than the threshold, the odometer update formula for straight-line driving based on slip rate correction is as follows:

[0031] .

[0032] According to a method for estimating the position of a differential unmanned vehicle based on slip rate correction provided by the present invention, step S6 includes: when the unmanned vehicle is in a driving state,

[0033] The calculation formula is:

[0034]

[0035] in, For The corrected displacement of the left wheel during the time period; When driving, the left wheel Slip rate at the moment; For the revolver Wheel speed at the moment; is the time interval, For time;

[0036] The calculation formula is:

[0037]

[0038] in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When driving, the right wheel Slip rate at the moment; is the time interval.

[0039] According to a method for estimating the position of a differential unmanned vehicle based on slip rate correction provided by the present invention, step S6 includes: when the unmanned vehicle is in a braking state,

[0040] The calculation formula is:

[0041]

[0042] in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When braking, the right wheel Slip rate at the moment; is the time interval;

[0043] The calculation formula is:

[0044]

[0045] in, For The corrected displacement of the left wheel during the time period; For the revolver Wheel speed at the moment; When braking, the left wheel Slip rate at the moment; is the time interval.

[0046] The present invention also provides a differential unmanned vehicle posture estimation system based on slip rate correction, comprising:

[0047] Motion parameter acquisition module: used to simplify the kinematic model of the differential unmanned vehicle based on the vehicle motion principle; install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; install a speed sensor on the unmanned vehicle to obtain the left and right wheel speeds;

[0048] Slip ratio calculation module: used to calculate the tire slip ratio based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and differential unmanned vehicle kinematic model;

[0049] Attitude acquisition module: used to install a gyroscope in the middle of the unmanned vehicle and use the gyroscope to obtain the vehicle's posture angle;

[0050] Odometer calculation module: This module determines whether the difference between the left and right wheel accelerations is greater than a threshold. If so, the odometer is updated using a slip-rate-corrected formula for cornering conditions. Otherwise, the odometer is updated using a slip-rate-corrected formula for straight-line driving conditions to obtain an updated value.

[0051] Position estimation module: used to estimate the current position of the unmanned vehicle based on the updated value.

[0052] The present invention also provides an electronic device comprising a processor, a communication interface, a memory and a communication bus. When the processor executes the program, the steps of any of the above-mentioned methods for estimating the position and posture of a differential unmanned vehicle based on slip rate correction are implemented.

[0053] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0054] The application provides a differential unmanned vehicle pose estimation method based on slip rate correction, a system and a device.

[0055] The sensors required in the six-wheel differential unmanned vehicle pose estimation method based on slip rate correction provided by the application mainly include an accelerometer, a wheel speed sensor and a gyroscope, are cheap, have strong anti-interference performance and have good economy. Since slip is a common phenomenon during vehicle driving, especially on a road surface with small ground adhesion, even large slip can occur. The occurrence of slip can cause the actual speed of the vehicle to be inconsistent with the theoretical speed, thereby affecting the accuracy of the odometer in the inertial navigation system (INS) and causing problems such as too large real-time pose estimation error. The size of the slip rate directly affects the positioning accuracy of the inertial navigation system (INS), and this factor is particularly prominent in the satellite denial environment. The six-wheel differential unmanned vehicle pose estimation method based on slip rate correction provided by the application can effectively compensate for the decrease in the accuracy of the integrated navigation in the satellite denial situation when calculating the real-time pose of the vehicle.

[0056] Additional aspects and advantages of the application will be described in part below, will become apparent from the following description, or will be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description.

[0058] Figure 1 is a flowchart of a differential unmanned vehicle pose estimation method based on slip rate correction provided by the application.

[0059] Figure 2 is a simplified result diagram of a six-wheel differential unmanned vehicle kinematic model.

[0060] Figure 3 is a vehicle perception sensor arrangement diagram.

[0061] Figure 4 is a six-wheel differential unmanned vehicle pose angle diagram.

[0062] Figure 5 is a structure block diagram of a differential unmanned vehicle pose estimation system based on slip rate correction provided by the application.

[0063] Figure 6 Figure 1 is a structural schematic diagram of an electronic device provided by the present application.

[0064] Reference signs:

[0065] 1, left wheel speed sensor; 2, right wheel speed sensor; 3, left acceleration sensor; 4, right acceleration sensor; 5, gyroscope; 101, motion parameter acquisition module; 102, slip rate calculation module; 103, attitude acquisition module; 104, mileage calculation module; 105, pose estimation module; 810, processor; 820, communication interface; 830, memory; 840, communication bus. DETAILED DESCRIPTION

[0066] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. The following embodiments are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0067] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are contained in at least one embodiment or example of the embodiments of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0068] The present application will be described below in combination with Figures 1 to 6 The present application.

[0069] Embodiments

[0070] As Figure 1 shown, Figure 1 Figure 1 is a flowchart of a differential unmanned vehicle pose estimation method based on slip rate correction provided by the present application. It includes the following steps:

[0071] S1: According to the principle of vehicle motion, simplify the kinematic model of differential unmanned vehicle;

[0072] S2: Install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations;

[0073] S3: Install a speed sensor on the unmanned vehicle to obtain the left and right wheel speeds;

[0074] S4: Calculate the tire slip rate based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and the differential unmanned vehicle kinematic model;

[0075] S5: Install a gyroscope 5 in the middle of the unmanned vehicle and use the gyroscope 5 to obtain the vehicle's posture angle;

[0076] S6: Determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold. If the difference is greater than the threshold, update the odometer according to a turning condition formula based on slip ratio correction. Otherwise, update the odometer according to a straight-line driving condition formula based on slip ratio correction to obtain an updated value.

[0077] S7: Based on the updated value, an estimate of the current position of the unmanned vehicle is obtained.

[0078] Specifically, such as Figure 2 The simplified kinematic model of the differential unmanned vehicle is shown as follows:

[0079] Replace all the wheels on the left side with one wheel, replace all the wheels on the right side with one wheel, and replace the car body with a rigid body.

[0080] Specifically, such as Figure 3 As shown, step S2 includes:

[0081] A left acceleration sensor 3 is installed on the vehicle body next to the left wheel to obtain the left wheel acceleration; a right acceleration sensor 4 is installed on the vehicle body next to the right wheel to obtain the right wheel acceleration;

[0082] Specifically, step S3 includes:

[0083] A left wheel speed sensor 1 is installed on the left wheel to obtain the left wheel speed; a right wheel speed sensor 2 is installed on the right wheel to obtain the right wheel speed.

[0084] Specifically, step S4 includes: when the unmanned vehicle is in the driving state, the slip rate calculation formula of the left wheel is:

[0085]

[0086] in, When driving, the left wheel Slip rate at the moment; When driving, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval;

[0087] The slip rate calculation formula of the right wheel is:

[0088]

[0089] in, When driving, the right wheel Slip rate at the moment; When driving, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

[0090] When the unmanned vehicle is in the braking state, the slip rate calculation formula of the left wheel is:

[0091]

[0092] in, When braking, the left wheel Slip rate at the moment; When braking, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval;

[0093] The slip rate calculation formula of the right wheel is:

[0094]

[0095] in, When braking, the right wheel Slip rate at the moment; When braking, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel Acceleration at the moment.

[0096] As shown in Figure 4 , the forward direction of the unmanned vehicle is the forward direction, the right turn direction of the unmanned vehicle is the positive direction, the forward direction and the lateral direction are perpendicular to each other, and in the embodiment of the present application, the numerical value of the pose estimation is calculated taking the vehicle starting from the stationary state as an example. Since the vehicle is in a stationary state at , the slip ratio of the left wheel at is , the slip ratio of the right wheel at is , the acceleration of the left wheel at is , the acceleration of the right wheel at is , the wheel speed of the left wheel at is , and the wheel speed of the right wheel at is . The wheel speed of the left wheel at is ; the wheel speed of the right wheel at is . According to the measurement of the gyroscope 5, the pose angle of the unmanned vehicle at the first moment is . The pose angle of the unmanned vehicle at the second moment is . The maximum driving speed of the chassis of the unmanned vehicle is ; the wheelbase is . The driving mode of the six-wheel differential unmanned vehicle is double-motor rear-wheel drive, and the left motor drives the left three wheels to rotate through a chain transmission, and the right motor drives the right three wheels to rotate through a chain transmission. From the conditions of the example, it can be known that the six-wheel differential unmanned vehicle in the example is in a driving state, and the slip ratio of the left wheel is obtained through the following formula:

[0097]

[0098] The slip ratio of the right wheel is obtained through the following formula:

[0099]

[0100]

[0101] Specifically, step S6 includes a threshold which is determined according to the maximum driving speed of the chassis of the unmanned vehicle, and the formula is:

[0102] ​

[0103] in, is the maximum speed of the unmanned vehicle chassis;

[0104] The update formula of the turning odometer based on slip rate correction is as follows:

[0105]

[0106] in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For the The position angle of the autonomous vehicle at the moment; is the wheelbase, For The corrected displacement of the left wheel during the time period, For The corrected displacement of the right wheel during the time period;

[0107] The update formula of the straight-line driving odometer based on slip rate correction is as follows:

[0108]

[0109] in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For The corrected displacement of the left wheel during the time period; For Corrected displacement of the right wheel during the time period.

[0110] When the autonomous vehicle is in driving state,

[0111] exist Corrected displacement of the left wheel within the time period Calculated by the following formula:

[0112]

[0113] in, For The corrected displacement of the left wheel during the time period; When driving, the left wheel Slip rate at the moment; For the revolver Wheel speed at the moment; is the time interval;

[0114] exist Corrected displacement of the right wheel within the time period Calculated by the following formula:

[0115]

[0116] in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When driving, the right wheel Slip rate at the moment; is the time interval.

[0117] When the autonomous vehicle is in braking state,

[0118] exist Corrected displacement of the right wheel within the time period Calculated by the following formula:

[0119]

[0120] in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When braking, the right wheel Slip rate at the moment; is the time interval;

[0121] exist Corrected displacement of the left wheel within the time period Calculated by the following formula:

[0122]

[0123] in, For The corrected displacement of the left wheel during the time period; For the revolver Wheel speed at the moment; When braking, the left wheel Slip rate at the moment; is the time interval.

[0124] According to the conditions in the example, the maximum speed of the unmanned vehicle chassis is , threshold Determined by the following formula:

[0125]

[0126] because ,Therefore, it is necessary to update the odometer according to the straight-line driving condition formula based on the slip ratio correction.

[0127] In the embodiment of the present invention, the unmanned vehicle is in a driving state, therefore,

[0128] exist Corrected displacement of the left wheel within the time period for:

[0129]

[0130] The six-wheel differential unmanned vehicle is in driving state. Corrected displacement of the right wheel within the time period for:

[0131]

[0132] The update formula of the straight-line driving odometer based on slip rate correction is as follows:

[0133]

[0134] In summary, according to the updated value of the odometer, the current position of the unmanned vehicle is estimated. Time compared to moment, in The displacement in the direction is 0.343m. The displacement in the direction is 0.06m.

[0135] The application provides a differential unmanned vehicle pose estimation method, system and device based on slip rate correction.

[0136] As shown in the Figure 5 application, the application provides a differential unmanned vehicle pose estimation device based on slip rate correction, comprising the following modules:

[0137] The motion parameter acquisition module 101 is used for simplifying the differential unmanned vehicle kinematics model according to the vehicle motion principle, installing an acceleration sensor on the unmanned vehicle to obtain the left wheel acceleration and the right wheel acceleration, and installing a speed sensor on the unmanned vehicle to obtain the left wheel speed and the right wheel speed.

[0138] The slip rate calculation module 102 is used for calculating the tire slip rate according to the left wheel acceleration, the right wheel acceleration, the left wheel speed, the right wheel speed and the differential unmanned vehicle kinematics model.

[0139] The attitude acquisition module 103 is used for installing a gyroscope in the middle of the unmanned vehicle and using the gyroscope to obtain the pose angle of the vehicle.

[0140] The mileage calculation module 104 is used for judging whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold value, if the difference is greater than the threshold value, updating the odometer according to the slip rate correction based turning working condition formula, otherwise, updating the odometer according to the slip rate correction based straight line driving working condition formula to obtain an updated value.

[0141] The pose estimation module 105 is used for obtaining the current pose estimation of the unmanned vehicle according to the updated value of the odometer.

[0142] Figure 6 An example of an entity structure diagram of an electronic device is shown in Figure 6 The electronic device can include a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 complete mutual communication through the communication bus 840. The processor 810 can call the logical instructions in the memory 830 to execute a differential unmanned vehicle pose estimation method based on slip rate correction, which comprises the following steps:

[0143] S1: Simplifying the differential unmanned vehicle kinematics model according to the vehicle motion principle;

[0144] S2: Obtaining the left wheel acceleration and the right wheel acceleration;

[0145] S3: Obtaining the left wheel speed and the right wheel speed;

[0146] S4: According to the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and differential unmanned vehicle kinematics model, the tire slip rate is calculated;

[0147] S5: The gyroscope is installed in the middle of the unmanned vehicle, and the pose angle of the vehicle is obtained by using the gyroscope;

[0148] S6: Determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than the threshold value, if the difference between the two is greater than the threshold value, then update the odometer according to the turning working condition formula based on the slip rate correction; otherwise, update the odometer according to the straight line driving working condition formula based on the slip rate correction;

[0149] S7: According to the odometer update value, the current pose estimation of the unmanned vehicle is obtained.

[0150] In addition, the logical instructions in the above-mentioned memory 830 can be realized in the form of a software function unit and sold or used as a separate product, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, server, or network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The foregoing storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and various program code storage media.

[0151] The device embodiments described above are only schematic, wherein the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment. Those skilled in the art can understand and implement without creative labor.

[0152] Those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary universal hardware platform, and of course can also be implemented by hardware, through the description of the above embodiments. Based on such understanding, the above technical solutions can be embodied in the form of a software product in essence or in the form of a part of the prior art. The computer software product can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the method described in each embodiment or some parts of the embodiment.

[0153] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

[0154] It should be noted that embodiments of the present disclosure can be realized by hardware, software or a combination of software and hardware. The hardware part can be realized by special logic: the software part can be stored in a memory and executed by a suitable instruction execution system, such as a microprocessor or a special designed hardware. Those skilled in the art can understand that the above devices and methods can be realized by computer executable instructions and / or included in processor control code, such as providing such code on a programmable memory or a data carrier such as optical or electronic signal carrier.

[0155] In addition, although the operations of the method of the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the operations must be performed in this specific order, or that all of the shown operations must be performed to achieve the desired result. On the contrary, the steps depicted in the flowchart can change the order of execution. Additionally or alternatively, some steps can be omitted, combined into one step, and / or divided into multiple steps. It should also be noted that the features and functions of two or more devices according to the present disclosure can be embodied in one device. Conversely, the features and functions of one device described above can be further divided into multiple devices.

[0156] Although the present disclosure has been described with reference to several specific embodiments, it should be understood that the present disclosure is not limited to the disclosed specific embodiments. The present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A method for position estimation of a differential unmanned vehicle based on slip rate correction, characterized in that: The following steps are involved: S1: Based on the vehicle motion principle, simplify the kinematic model of the differential unmanned vehicle; S2: Install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; S3: Install a speed sensor on the unmanned vehicle to obtain the left and right wheel speeds; S4: Calculate the tire slip rate based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and the differential unmanned vehicle kinematic model; S5: Install a gyroscope in the middle of the unmanned vehicle and use it to obtain the vehicle's position angle; S6: Determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold. If the difference is greater than the threshold, update the odometer according to a turning condition formula based on slip ratio correction. Otherwise, update the odometer according to a straight-line driving condition formula based on slip ratio correction to obtain an updated value. S7: Based on the updated value, an estimate of the current position of the unmanned vehicle is obtained.

2. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: The kinematic model of the differential unmanned vehicle is: Replace all the wheels on the left side with one wheel, replace all the wheels on the right side with one wheel, and replace the car body with a rigid body.

3. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S2 includes: An acceleration sensor is installed on the vehicle body next to the left wheel to obtain the left wheel acceleration; an acceleration sensor is installed on the vehicle body next to the right wheel to obtain the right wheel acceleration; Step S3 includes: A speed sensor is installed on the left wheel to obtain the left wheel speed; a speed sensor is installed on the right wheel to obtain the right wheel speed.

4. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S4 includes: when the unmanned vehicle is in the driving state, the slip rate of the left wheel is calculated as follows: in, When driving, the left wheel Slip rate at the moment; When driving, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval, For time; The slip rate calculation formula of the right wheel is: in, When driving, the right wheel Slip rate at the moment; When driving, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

5. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S4 includes: when the unmanned vehicle is in a braking state, the slip rate of the left wheel is calculated as follows: in, When braking, the left wheel Slip rate at the moment; When braking, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval, For time; The slip rate calculation formula of the right wheel is: in, When braking, the right wheel Slip rate at the moment; When braking, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

6. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S6 includes: threshold Determined according to the maximum driving speed of the unmanned vehicle chassis, the formula is: in, is the maximum speed of the unmanned vehicle chassis; When the difference between the left wheel acceleration and the right wheel acceleration is greater than the threshold, the slip-rate-corrected turning odometer update formula is as follows: in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For the The position angle of the autonomous vehicle at the moment; is the wheelbase, For The corrected displacement of the left wheel during the time period, For The corrected displacement of the right wheel during the time period; the unmanned vehicle's forward direction is direction positive direction, The positive direction is the right turn direction of the unmanned vehicle. Direction and The directions are perpendicular to each other, For time; When the difference between the left wheel acceleration and the right wheel acceleration is not greater than the threshold, the odometer update formula for straight-line driving based on slip rate correction is as follows: 。 7. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 6, characterized in that: Step S6 includes: when the unmanned vehicle is in the driving state, The calculation formula is: in, When driving, the left wheel Slip rate at the moment; For the revolver Wheel speed at the moment; is the time interval; The calculation formula is: in, For the right wheel Wheel speed at the moment; When driving, the right wheel The slip rate at the moment.

8. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 6, characterized in that: Step S6 includes: when the unmanned vehicle is in a braking state, The calculation formula is: in, For the right wheel Wheel speed at the moment; When braking, the right wheel Slip rate at the moment; is the time interval; The calculation formula is: in, For the revolver Wheel speed at all times.

9. A system for estimating the position and attitude of a differential-speed autonomous vehicle based on slip rate correction, for executing the method for estimating the position and attitude of a differential-speed autonomous vehicle based on slip rate correction as claimed in any one of claims 1 to 7, characterized in that: include: Motion parameter acquisition module: used to simplify the kinematic model of the differential unmanned vehicle based on the vehicle motion principle; Install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; Install speed sensors on the unmanned vehicle to obtain the left and right wheel speeds; Slip ratio calculation module: used to calculate the tire slip ratio based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and differential unmanned vehicle kinematic model; Attitude acquisition module: used to install a gyroscope in the middle of the unmanned vehicle and use the gyroscope to obtain the vehicle's posture angle; Odometer calculation module: used to determine whether the difference between the left and right wheel accelerations is greater than a threshold. If the difference is greater than the threshold, the odometer is updated according to the turning condition formula based on the slip rate correction. Otherwise, the odometer is updated according to the straight-line driving condition formula based on the slip ratio correction to obtain an updated value; Position estimation module: used to estimate the current position of the unmanned vehicle based on the updated value.

10. An electronic device comprising a processor, a communication interface, a memory and a communication bus, characterized in that: When the processor executes the computer program, the steps of the method for estimating the position posture of a differential unmanned vehicle based on slip rate correction as described in any one of claims 1 to 7 are implemented.

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